Bonanza F33A "LDG GR POS" circuit breaker

RussR

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During an IPC yesterday with the owner of a 1993 F33A Bonanza, I surreptitiously pulled the "LDG GR POS" circuit breaker in an attempt to see if he would notice the lack of green lights as he lowered the gear at the FAF.

In the attached picture, this is the 4th one on the top row, a 5A breaker.

I thought "LDG GR POS" meant "Landing Gear Position (lights)" and expected the gear to go down but just the indicator lights to not work.

Well, he did notice, because the gear did not go down either. Good on him for noticing that. So we still had an effective training event.

If I had pulled the 30A "LDG GEAR" breaker (first one on bottom row), I would have expected this behavior. But not with the "LDR GR POS" breaker.

So, one of two things - either I don't understand what "LDG GR POS" means here, or I don't understand how the 1993 F33A gear warning system works. Or, I guess, something's wrong with his airplane.

I did look in the POH and it's not very detailed on this topic. I did not see a diagram of the electrical system in there either. Anybody have any knowledge about this and can steer me right?

Thanks.

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I suspect that LDG GR POS is also the Landing Gear Control circuit, and LDG GR is just the motor...they haven’t put the full motor amperage through the gear switch for a few years now. ;)
 
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Clearly you’re not qualified to give dual in a Bonanza.

In defense of OP, my BPPP CFI training and checkout did not cover that breaker either. You need to fish deep into the wiring diagrams to see all of the things that circuit feeds. It's a lot. :)
 
Clearly you’re not qualified to give dual in a Bonanza.

No smilie, but I considered that a joke anyway until subsequent posters made me wonder. So I laughed. But if I shouldn't have, no worries, let me know!

this is why CFI's shouldn't play with things.....o_O :D

Darn CFIs always "breaking" things. Starts with those instrument covers and goes from there! Pretty much a standard part of my FR (I know this was an IPC, but that doesn't make it off limits) to pull a gear CB in any retractable airplane. Seen too many people get complacent.

In defense of OP, my BPPP CFI training and checkout did not cover that breaker either. You need to fish deep into the wiring diagrams to see all of the things that circuit feeds. It's a lot. :)

I agree I don't remember that from the (excellent) BPPP training. I did all the training courses but never did take the official checkride. And it's not something that's in the POH anyway.

Interesting comments so far...

Says a lot about @RussR that he can publicly post something like this to learn from it knowing he would likely take some heat. Not sure I would have the courage to do that.

That's how the rest of us can learn, both systems and CFI technique.

Aw heck, I didn't see anything as "taking any heat" yet. And even if so, that's okay, to me part of being a good CFI isn't knowing everything, but being willing to learn. And a big part of learning is admitting you don't know something. But thanks!

In the last 30 days I have either piloted or taught in 11 airplane types. I will admit it is sometimes hard to keep them straight:
Piper PA-32
Cessna 172
Mooney M20J
Cessna Citation Encore
Cessna 340
Piper PA-24
Bonanza V35B
Cessna 206
Cessna Citation V
Bonanza F33A
Cessna 421C

So I certainly can't be an expert on every CB on all of them.

I just think that label is a tad judgemental. Nothing wrong with Bonanza gear that I am aware of.

That was my first thought when I read it too! POS gear... Of course, there are other airplanes I would put that label on before the Bonanzas.
 
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@RussR

I’m just doing my IR now, but I think it’s best you learn all of the systems in your check aircraft before creating failures. That may necessitate a pre-flight with the owner/pilot where you go over all the systems. That’s what you are being paid for. Pulling breakers not knowing the outcome is poor behavior. And a safety of flight issue in my opinion.
 
In the last 30 days I have either piloted or taught in 11 airplane types. I will admit it is sometimes hard to keep them straight:
Piper PA-32
Cessna 172
Mooney M20J
Cessna Citation Encore
Cessna 340
Piper PA-24
Bonanza V35B
Cessna 206
Cessna Citation V
Bonanza F33A
Cessna 421C

So I certainly can't be an expert on every CB on all of them.

Absolutely. It's impossible to be a systems expert for every single training event when you fly many airplanes. Not a big deal. No 'heat' should be coming your way for this.

I've certainly also been surprised by the behavior exhibited from the subject aircraft for a given simulated failure, usually avionics. It's hard to "fail" components anymore with CBs, especially with the integrated avionics suites we see out there nowadays -- as various components might 'ride' on one CB.

For training, the art and science of how a CFI provides a rich learning experience for the client involves some experimentation at times.
 
@RussR

I’m just doing my IR now, but I think it’s best you learn all of the systems in your check aircraft before creating failures. That may necessitate a pre-flight with the owner/pilot where you go over all the systems. That’s what you are being paid for. Pulling breakers not knowing the outcome is poor behavior. And a safety of flight issue in my opinion.

That's a fair viewpoint, but I have to disagree. Mostly it comes down to your last sentence.

In most general aviation aircraft, which circuit breaker would cause a safety of flight issue if intentionally pulled for training on a clear VFR day? Would any of them actually cause a safety of flight issue? Remember, the airplane will fly just fine if you turn off the entire electrical system, including alternator and battery switches.

However, please don't think I go around haphazardly pulling breakers. I pulled an appropriate one to create the training event desired. And it did create an effective training event. So as far as I am concerned, missed accomplished. The fact that it had additional effects created an enhanced training event, with no safety impacts. It is not unrealistic for that breaker to pop, and now he (and I) both know the effects.

So for an IPC (or a FR), you recommend we conduct a pre-flight lesson on all the systems in the airplane, to include every circuit breaker, and system schematics that are not in the POH? I'd be happy to do that, but it would mean an all-day lesson instead of a couple-hour lesson. While certainly a great idea, few pilots would agree to pay for that.
 
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I knew a bright older CFI that thought it would be brilliant to remove a landing gear indicator bulb in a 182RG.....it needed to be there....and the gear collapsed on landing. :confused:
 
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Rather than throwing stones at the OP, maybe this sharing of information would encourage you to to dig deeper into the aircraft you fly. Every aircraft I have flown has some small idiosyncrasy like this.
 
Rather than throwing stones at the OP, maybe this sharing of information would encourage you to to dig deeper into the aircraft you fly. Every aircraft I have flown has some small idiosyncrasy like this.

I can stump anyone, even myself. Give me 10 minutes with the AFM and the TCDS and I can come up with a series of questions virtually no one can answer, not even long-time aircraft owners, without digging around. It's a rather pointless exercise, so I keep things realistic.

Much better to just have a chat about "hey, why does this work this way?" and enjoy a nice collective learning moment. Thanks, Russ.
 
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